September 22, 2009

It's very common for people to invent an idealized idea of the past to support a point relevant to their current beliefs. For example, conservatives often refer to a mythical American past in which extended patriarchal families lived together in harmony. Demographers who have studied US census records found that the only time significant numbers of Americans lived in three generation families was during the depression of the 1930s when they were forced into that situation by poverty and moved out as soon as times improved. They typical pattern in the US has always been for children to leave home as soon as they could and to live in pair bonds--or mother-headed families which were common thanks to death or desertion.

There is a similar phenomenon among the low carb community which disturbs me, since I've been academically trained in both the study of Anthropology (bachelor's degree, University of Chicago) and History (Masters Degree, University of Massachusetts studying under Stephen B. Oates). There is enough data here and now to support the utility of cutting the carbs out of our diet that we don't have to invent an idyllic past to support it.

The two Idyllic Fantasies that bother me the most are these: a) The Paleolithic Perfection scenario and b) The idea that Heart Disease was unknown until very recently. Let's have a brief look at why neither of these arguments are accurate or relevant to us today.

"Paleolithic" refers to all hominids--Neanderthals and modern humans--living before the discovery that plants could be domesticated which took place around 12,000 BC. In the fantasy, Paleolithic people lived on game, ate low carb diets, and were far healthier than everyone ever since.

The fallacy here is that we know very little about real Paleolithic life. All we have are a very limited collection of burials and stone tools with the occasional find of traces of fiber, fossilized seeds, and non-human bones which may or may not be the remains of the hominid meals, since animals often deposit kills in the caves where hominids dwelled at some other time. Most of our beliefs about "paleo" peoples derive from study of isolated groups of early 20th century hunter/gatherers. How similar their habits were were to paleo people of 20,000 years ago is impossible to know.

The argument is made that skeletons of agricultural people from the next, Neolithic, period are shorter than those of the Paleolithic period and show signs of disease not found in the earlier bones. Attributing this to diet makes us feel good about our low carb eating, but it ignores a few key facts: The paleolithic lifestyle winnowed out all but the most healthy and robust very quickly. Human population in the paleolithic period, though it lasted almost 2 million years stayed nearly constant--hominids just barely managed to replace themselves even though females were probably having a baby every 3 years. That's because most babies, all but the most robust--died.

The reason for this is obvious to anyone who has studied the experience modern hunter/gatherer peoples--periodic famine ravaged the population on a regular cyclical basis. The very few hunter/gatherers extant in the early 20th century when they were discovered by anthropologists were those who lived either in extremely isolated environments where agriculture was impossible, or in unusually rich biospheres that made hunting/gathering attractive enough that they did not, like humans in 90% of the rest of the planet, welcome agriculture with wild enthusiasm as soon as they learned of it.

The reason most humans took to agriculture with enthusiasm was precisely because it raised the likelihood of survival. Storing food gets you through famine and allows your children to survive the three months with nothing to eat that otherwise would kill them. It is only after the adoption of agriculture that human population starts to soar.

Those robust skeletons hide another ugly truth. Older individuals or those who have anything wrong with them quickly fall by the wayside when living a migrant paleolithic lifestyle. There is no way a hunting gathering band can carrying along people who can't walk many miles every day. Any severe illness or disability lasting for more than a few weeks will mean that the individual must be abandoned because the group must keep moving to find food. Game isn't stupid and it avoids hunters who stay in one place. Gatherers (i.e. women who supply most of the calories in contemporary hunting/gathering societies) must keep moving because edibles are scarce, seasonal and an area gets picked out pretty fast. So people don't develop the disease of age, like arthritis, because they don't live long enough to do so.

So the apparent "health" of the paleolithic remains is mostly due to the fact that most of the paleo people never made it to adulthood and when they did, they died relatively young--that and the fact that we have very few remains from that period on which to draw our conclusions. Hundreds rather than the tens of thousands from the later period.

The Inuit, so beloved of Paleo fantasists, lived a life of such extreme deprivation that it is hard to understand why anyone would make them the poster child of any diet. While most Native American peoples developed agriculture thousands of years before--the Inuit lived isolated in an environment where it is impossible to grow anything. They did what they could to survive but their numbers were small and their health and that of their children not anything you would envy--their real diet included the stomach contents of their prey--the semi digested vegetable matter now digested since the cellulose had been broken down--and entirely raw meat and fat. No Inuit survived to age 7 who was not metabolically able to cope with that diet. Natural selection works that way.

The other fantasy I'm seeing more and more appearing on the health blogs is the idea that heart disease didn't exist until the early 20th century. A good example of this kind of thinking occurs towards the end of this otherwise reasonable blog post: Fat Head: Margarine and Mother Nature. The graph looks impressive, but the reality behind the figures on the graph drains it of the meaning the blogger would like to assign to it.

There are a lot of reasons why heart attack deaths rise. Primary is this: The single strongest epidemiological risk factor for heart attack is age. This is something you don't hear because there is a huge industry devoted to terrifying you, young, about your likelihood of getting a heart attack so it can sell you expensive products and medial services.

But heart attacks have always been relatively rare in people younger than 55. and when they occur they are usually due to specific genetic conditions or side effects of other serious disease processes. Because until the second half of the 20th century a much smaller number of people lived into the decades where heart attacks occur, it should not surprise us that heart attacks were rare.

The reason that Social Security kicks in at 65 is that back when pensions were first instituted (in Germany in the 1880s), not all that many people lived to be much older than 65, so a program that paid pensions to the few rugged survivors was quite economically sustainable. To achieve the equivalent demographic effect today, we would have to raise the age for old age pensions to at least 80, perhaps higher.

People a hundred years ago did not live to die of heart attacks because injury and bacterial infections took a huge toll. An infected pimple could become deadly--my mother remembered children she went to school with dying of just that kind of infection.

Another reason why people did not live long enough to develop heart disease was that until the 1950s there were no effective treatments for high blood pressure so people who developed cardiovascular disease who nowadays might die of a heart attack were much more likely to die of stroke or kidney failure caused by high blood pressure first. When Franklin Roosevelt's blood pressure in 1944 was measured at 210/110 his doctors had no way of lowering it.

The physical labor so adulated by today's gym culture did not lead to a longer life, it wore people out. There is a huge difference between spending an hour or two at the gym and putting in 12 hours six days a week at the steel mill, coal mine, or farm. Physical labor takes a very big toll on the body over time. Add the tuberculosis bacillus to the mix, a disease that preys on overworked crowded populations--or syphilis, one of the most frequent killers in the 19th century, though rarely one that appeared on death certificates, stir in a pinch of cholera, typhoid and other water-borne killers, and you have a very good explanation for the lack of heart disease deaths. Most people didn't live long enough to die of heart attacks.

Heart attacks probably did occur among those lucky enough to make it into their 60s, but in the 19th century and early 20th century differentiating a heart attack from a fatal stroke might have been very difficult. When the death occurred at home as was usually the case, an autopsy would have rarely been performed. When the death involved a person in their 60s or older the diagnosis was likely to be, "Old age."

That people did in fact have nonfatal heart attacks in those times is evidenced by the frequency with which historical sources refer to "dropsy" which sounds a lot like heart failure--the condition that follows nonfatal heart attack. The many older people with "dropsy" probably had serious heart disease. But there was no way of knowing this and when they died of "dropsy," or after a "fit" that was what went on their death certificate.

Finally we should not forget that a major reason for the growth of heart disease in the 20th century was the spread of cigarette smoking which took off after WWI when cigarette manufacturers ensured the troops were given cigarettes along with their rations.

Wikipedia summarizes the epidemiology thus:

The widespread smoking of cigarettes in the Western world is largely a 20th Century phenomenon – at the start of the century the per capita annual consumption in the USA was 54 cigarettes (equivalent to less than 0.5% of the population smoking more than 100 cigarettes per year), and consumption there peaked at 4,259 per capita in 1965. At that time about 50% of men and 33% of women smoked (defined as smoking more than 100 cigarettes per year). By 2000, consumption had fallen to 2,092 per capita, corresponding to about 30% of men and 22% of women smoking more than 100 cigarettes per year, and by 2006 per capita consumption had declined to 1,691; implying that about 21% of the population smoked 100 cigarettes or more per year.

In fact, with all the horrors of the modern diet, heart attack death rates in the age group most prone to heart disease have been dropping steadily over the past two decades. This is largely due to anti-smoking efforts and the advent of effective blood pressure medication.

There is no question that cutting down on carbohydrates makes a huge difference in the health of people with diabetes and pre-diabetes. There is no question either that the frankenfood industry is selling products full of highly unhealthy lab created chemicals to an unwary public, and that some of these foods, like the margarine described in the blog post cited above, do worsen our health.

But let's not fall into the trap of imagining that over all health was better in the past and that the reason for this was dietary. For most of human (and hominid) history, food was scare and hard to come by. Starvation was always a possibility. For anyone dwelling in the latitudes where winter brings snow, six months of the year were the "starving time" and agriculture was all that made it possible for large populations to colonize those areas successfully.

Living long enough to develop the "diseases of civilization" was, in many ways, a triumph. You have only to look at the curve of population over the past twenty thousand years to see, in evolutionary terms, which diet and lifestyle made people the most successful in terms of reproductive success.

Diet is an important tool for controlling diabetes, but it is not a panacea, and there is a huge understandable, human tendency to hope that by controlling what we can control--the food we put into our mouth, we can somehow live forever. Those of us with diabetes actually do have a condition where what we eat makes a huge difference in our health outcome but most other human ailments, however, do not fall into this pattern.

Let's do what we can to improve what we eat. Let's avoid foods that obviously harm us, but let's not resort to fantasy and nostalgia to back up our dietary arguments. There is plenty of good data in the present to do so.

Making inflated arguments, or imposing "truths" that are true only for those of us with disrupted glucose metabolisms on everyone blows up in our face. The main reason so many studies of the effectiveness of the low carbohydrate diet come up with tepid (though positive) results is that they involve groups of people that do not have blood sugar problems, for whom the low carb diet is not any more effective than other diets. Were researchers to evaluate the low carb diet as a treatment only for people with abnormal glucose, not as a panacea for all humans including the majority whose glucose metabolism is normal, we'd end up with much more compelling data.

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comments:

Thanks for this, Jenny. While the arguments for Paleo eating sound intuitively correct, so does the popular statement that "fat makes you fat."

Often, common sense deductions will guide us into healthy eating patterns. But as you have shown, sometimes more data will reveal that our common sense is based on faulty assumptions. That's why, in science, we can't just rely on a few observations or use logical deductions. We always have to do the experiments. Fortunately for us, there are lots of studies that include actual experimental data that show that low-carbing works.

I suggested on a popular physician's blog that the world was having trouble feeding it human population even with a grain diet, and that increased population, and environmental degradation were also threats.

I was assured by the blog owner that the environmental threats were all hogwash, and by site posters that it really would be easy to feed the whole planet a meat based diet.

I have got good information on that site from time to time, but I no longer regularly read it. This post of yours states very well my thoughts. Thanks

An excellent post. It reminds me strongly of an article - around 30 years ago? published in one of his collections - by the late Isaac Asimov that argued strongly and cogently against those who extolled some mythical, perfect past as the answer to all our modern ills,and completely ignored the rampant typhoid, cholera, appalling infant mortality rates extant then, etc. Anyone now in favour of giving up antibiotics, modern sewage plants etc etc ? No, I thought not.... For those interested in reading it, the article was ( somewhat caustically ! ) titled ' Best Foot Backwards' and I recommend it.

I think you are overreaching in your reference to that other blog (I read the same). My interpretation of that blog writer's position isn't that he thinks there are no environmental threats in the world (or are hogwash), only that he isn't convinced of the unproven theories of human-caused global warming/climate change.

You are right that people are still starving, even with grain as a staple throughout much of the world. But in the modern age, starvation is mostly due to extreme poverty and more influenced by wealth accumulation and politics rather than by food production, whether grain-based, meat-based, or a mixture.

It's always a good idea to step back from a position and view it from different angles. The new view sometimes provides a better perspective, though not always. But the view from a different angle is nearly always worthwhile.

His words are accurately described by the word "hogwash", probably some other dismissive word. Specifically he made the comment about David Montgomery, an eminent scientist. And no I do not believe that sensible people can think that the earth's population could all eat a meat based diet. There is not enough arable land.

You have, in a blog post ten times more eloquent than anything I could write, basically summed up all the reasons why the low carb community needs to get a reality check.

Ahhhh how cathartic it is to vicariously revel in such pure PwnAge.

If I were going to take to the task of bashing "paleos", however, I would put more emphasis on the aspbergers traits, mysogyny, and/or libertarian leanings of these individuals.

"Paleo" living, whatever that means, is basically low carb's version of veganism/frutarians and various other non-meat eating extremists. They make normal vegetarians uncomfortable, but they run amok in vegetarian circles, weilding power they really dont and shouldn't deserve. It's a type of thinking that prays on the vulnerable soft spot in certain human brains... the types of human brains prone to religious belief and other forms of selective psychosis. The type of brain, and part of brain, which is capable of extreme fanatical faith-based fantasy driven beliefs which are rigid, impervious to logic or reason, and can even result in psychotic symptoms like delusions or hallucinations (e.g. religious people who "see" signs from god or "feel" god telling them to do something).

Paleo is just another set of religious instructions imprinted on this "cRaZy" part of the brain.

I am so, so thankful I am not a religious person.

I am capable of strong irrational beliefs, I have had an eating disorder... but I am sparred the humiliation of delusional unwavering belief that seems to attack some individuals. Having "faith" is a lot like being psychotic... everyone else thinks you're crazy and funny but you are dead damn serious.

This brings me to another idea: why is it that "EATING" is so frequently the gateway to religious belief? People get "weird" about food (extreme, rigid, black or white) in a way that is usually reserved for either religious belief or frank psychotic delusions.Veganism, paleos, anorexia nervosa, CRON, fasting, juicing... the details are different but the underlying mechanism is the same. Eating weird leads to thinking weird, in a very specific way (rigid, irrational, fantastical, vaguely similar to psychosis).

As I have observed my own reaction to food restriction, I believe that any time food is restricted, certain people's brains are vulnerable to a hyperdopaminergic state which leads to such distortions, rigidity, fixations, preoccupations, which leads to vaguely psychotic thinking.

This is why it is so common for a person to innocently manipulate diet, and come out a few weeks later believing that all diseases are caused by eating carbs... or , believing that she is morbidly obese and must lose to 85 pounds just to be safe... or, bees have rights and we are evil monsters who are stealing hteir honey....

I mean, you get the idea.

However crazy a person is, they are generally a lot crazier after manipulating their diet.

This can't be incidental.

There is a lot of science to support the idea of dopamine dominance during food / energy restriction, too. Speaking personally I damn well know not eating can sometimes make me as crazy as if I had taken stims.

So what if someone is an eminent scientist - if the facts do match their assertions or the science is still unclear, then it does not matter how eminent they are.

Gary Taubes, for one, has made a career of writing books about the stupidity of eminent scientists in fields as diverse as nutrition and physics.

As I sit here in Australia watching the Antarctic ice cap grow, I still wonder about the relative importance of the man made warming versus other influences upon the global environment.

When, as a statistician, I read the literature on global warming, I am so far unconvinced that man made warming is the major cause. Remember, association does not equal cause. That is all that Eades has argued. There is, of course the black swan argument, which you have not advanced, that a little insurance against the extreme that the alarmists might be correct, may still on balance be worthwhile.

Similarly, if you wish to make an assertion regarding the inability of the planet to support a meat based life style, i suggest you back it up with some facts regarding causality, such as a RCT with crossover of the total input to mouth carrying capacity of similar pieces of land used to support mono- vegetable or meat, or mixed production cultures.

If you cannot show me such results, then i suggest you stop tarring those who do not agree with your assertions as not being sensible people.

I have seen the same effect occur less dramatically in a religious cult where a limited diet produced a combination of pleasing psychic effects combined with a more disturbing ones.

The other factor at work with odd diets is that people have a natural tendency to avoid those who do not eat the way they do so setting up an exclusionary diet can be a way of bonding people to a certain group and getting them to avoid others.

The vegan teen who refuses to eat the family food is making a huge statement about chosen association.

When I had to start eating low carb because of my diabetes, the mostly vegetarian people I associated with started making me feel like a pariah when I'd bring meat to potlucks, which gave me a strong sense of how powerful that associative effect connected to food is.

Thanks, Wooo and Jenny, for reminding me of the religious and group bonding aspects of eating in a particular way.

I do low-carb because it works, not because it makes me feel superior to other people or because it makes me part of an exclusive group with special knowledge. I have looked with amazement at people who follow fruitarianism to the point of losing their livers, or pro-anorexia to the point of losing their lives.

After reading your comments, now that I think about it, there must also be low-carbers who follow a particular path of low-carbing based on group acceptance, using pseudo-science as a rationale, while being unwilling to consider genuine experimental evidence if it brings their beliefs into question.

I have no doubt that the insulin resistant diabetic should limit carbohydrate intake to amounts that do not spike blood sugar to harmful levels or cause circulating insulin levels to go above-normal after food. At the same time the 'evangelical' zeal of some low carbers to blame carb consumption for all that ails humanity makes me laugh out loud. Some of these low carbers are no less 'associative' than their counterparts, the 'evangelical' vegans/veggies. If you don't happen to be a low carber (as per the definition of these evangelical low carbers) they definitely make you feel a pariah, just the way Jenny says she felt in the company of adamant vegans/veggies when she brought meat to their potlucks.

*Thank you.* I'm new to the Paleo/ low-carb/ WAPF (not to equate them) blogging communities, and have been bristling, based on my pretty basic anthropological education, against common assumptions about what Paleo people ate, assumptions that seem pretty retro to me.

In my 2002 anthropology class, hunter-gatherers were no longer called that, but rather foraging-hunting societies, with foraging first because it was the more significant source of food. I also remember a great article in Scientific American quite a while ago (I'm going to look it up) that featured new research (not coincidentally by women) into the diets and the roles of women (the two are always linked) in European Stone Age cultures.

It blew the idea of big game hunted by men being the main source of food out of the water. It found evidence of *group* hunting (women, children, and men) of *small* game, using nets (which don't last as long as spear tips, so you have to look differently for the evidence); a higher vegetable intake (tubers, etc.), year-round, than had been previously assumed; and that most of the mammoth bones, etc., showed evidence that they were scavanged rather than hunted, from the cut marks on them.

Yes, there were cave paintings of big hunts, but the researchers posited that killing a large beast would be such an event it would be celebrated and talked about for a long time. In fact, the cost- benefit ratio of routinely hunting big game, in terms of energy expenditure, personnel, risk of injury, and risk of coming home empty-handed, was fairly high, thus, if other ways of getting food were more readily available, they'd be preferred.

Of course, this is just one human group, but it is one of the groups you might guess to be more hunter than gatherer, given the climate (compared to tropical environments and so on), but it may not have been so.

I've noticed that Paleo appeals to a lot of guys, and there are a lot of guy assumptions that go with the diet much of the time. Yes, I know there are proud Paleo girls out there, too. I just think Jenny's take-home message is a good one - enjoy your diet, but don't assume it's based on much that's certain that our ancestors did. If there's anything we know, diets varied a lot - humans' main evolutionary advantage is our adaptability - and that our view of prehistory is pretty darn murky.

One thing to keep in mind, folks: Just as there is a fanatical vegetarian/vegan POV and fanatical low-carb/"Peleo" POV, there is also a fanatical "middle of the road" POV.

Any group that is significantly unlike our group can easily be labeled weird or odd or fanatical. Just because we belong to a group that is recognized as "normal" doesn't exclude us from those labels, nor does it imply we are right.

Excellent post! I follow a low-carb, sugar-free, PUFA-free diet because it works for me and keeps my BG under control without medications - and I feel excellent on it. But I hope that I would never be considered a zealot on the subject. I think it has tons of benefits for most folks compared to the SAD, and tons of processed foods. Surely eating "real" food has to be better for most people.

But I have come across zealotry in the low carb/paleo world. Zero carbers seem more prone it it than mere low carbers. But some of the paleo types are really hard core! And they do tend to be men, mostly. At least the ones I've come across.

Low carb works well for me (well, except in weight loss, not doing much for me there) but I'm not about to hyperventilate if I put a slice or two of tomato on my hamburger - a real no-no in both the zero carb and hardcore paleo worlds.

As a non-diabetic low-carber, I find low carb works well to control my weight. The current obesity epidemic does not rely on speculative history, but is well founded in statistics. And some of the anthropologocal studies such as those by Weston Price demand serious consideration. While I agree that the Paleo enthusiasts go overboard, relegating low carb only to diabetics is swinging too far in the other direction.

Helen – yes, most “paleo living” is entwined with misogyny (and extreme antisocial/antigovernment ideologies like libertarianism). It’s a very conservative white male kind of thing, but not your grandpa’s conservative white male… more like the starbucks internet boom aspbergers geek modern form. It’s basically a fantasy for a lot of guys. The irony is most of these guys don’t have the courage to be real chauvinists so they do it in this passive feminine way of fantasy and imagining themselves as cavemen. LOL. It would be cute if it weren’t so annoying/angering.

As for female paleos… I just don’t get that at all. I can only imagine they don’t realize this cowboys and indians game of glorifying the fantasy of a free virile hunter is intrinsically misogynistic. They are basically misinformed about human nutrition, human evolution, and are deaf/dumb to the real game behind “being paleo”.

I really shouldn’t let it bother me. If it makes people happy to fantasize about being cavepeople, let them have at it! I don’t get “adult babies” (google on encyclopedia dramatica, this is not advised if you are easily skeeved) but I am not about to crusade against them.

The thing that bothers me about paleos is how obnoxious they are. They go around the forums acting like they are eating “the real human diet” (they literally started calling it that) and other such nonsense. I mean, take that crap somewhere else plz thxu.

Meat messes up my blood sugar and mood when I eat too much of it anyway. It only makes sense, the only time people would metabolize lots of protein if they were eating a lot of food, so it makes sense if excessive quantities of protein trigger a similar reaction as excessive carbohydrate. Fat is where it is at BB, especially monofats. NUTS I LURVE U.

Kyle – Hate to disagree but “fanatical middle ground” is a contradiction. Believing the middle ground is the most cautious and rational position is not fanaticism, it’s common sense.

Nielso – not just diabetics, but hypoglycemics and many types of obese people and epileptics etc. I don’t think anyone literally meant “only diabetics”. What was implied is that people who have special health concerns sometimes require certain dietary restrictions. When the restriction is carbs, most people think of diabetics and this is a diabetes-centric blog, so it was stated as diabetes.

But no, I don’t think any normal healthy person needs to eat low carb. Unfortunately most people are not normal and healthy thanks to our toxic environment.

1. I live with a card-carrying Libertarian and the paleo guys don't remind me of him at all. So the libertarian label may depend upon how you define the word.

2. I've only read a few paleo blogs, but I didn't come away with the impression that those particular ones were anti-women. They might have been puzzled by women (and many men are) but I didn't see the mysogyny you speak of. Again, this may be a difference in definitions.

Now for the part I definitely agree with:

You said, "[Paleos] go around the forums acting like they are eating “the real human diet”..." If they call it that, it's quite humorous. I remember slogging through The Bear's postings at Active Low Carber, The real human diet is a totally carnivorous one. By the end of it, it appeared to me that he was anti-science more than anything.

When I wrote my blogpost for this week I was surprised to find that the early 20th century Inuit ate things like polar bear, seal, whale skin and rotten fish. In other words, the issue is not whether they ate the stomach contents of the animals they killed, but what kinds of animals they were actually eating. Somehow I don't think the Nutrition Facts for whale skin would be the same as those on a tube of Wal-Mart hamburger.

People are free to eat what they like. But they are not free to call it a scientifically based diet when it manifestly is not.

To comment on the second assumption addressed in this post (heart disease), when I was growing up, the 35-45 age range was considered "prime heart attack years" for men. The men affected at this age would suffer a single, massive heart attack (possibly we call it something else now, but basically the heart completely stopped), and with emergency services and diagnostics what they were (or were not) in the 1960's and 1970's, these people would often be dead by the time the ambulance arrived, or they would die en route to the hospital. After age 50-55, a first "heart attack" was often milder and more likely survivable.

What I don't have are hard numbers, so I don't know if this was more popular wisdom than medical statistics -- and also, this was in the period of time where smoking was still very popular and ulcers were believed to be stress- and/or diet-related...

I've read your opinion on the low carbing issue. As I understand, you're actually not active on the fields you studied, correct me if I'm wrong.

I have just some criticism of your article. Early on you state that:

"...the fallacy here is that we know very little about real Paleolithic life",

just to put the following lines later, my interpretation here, as a fact:

"Human population in the paleolithic period, though it lasted almost 2 million years stayed nearly constant--hominids just barely managed to replace themselves even though females were probably having a baby every 3 years. That's because most babies, all but the most robust--died."

From actual knowledge from human DNA data, it looks like that your assesment is incorrect and that around 100'000 to 60'000 years ago, probably there were less than 20'000 humans alive, because the Toba eruption event.

As a trained anthropologist you should have knowledge of this theory/event. Unless that, by "nearly constant", you also included the "occasional" population decrease by probably 99%...

Then, how do we/you know that most babies died if we/you know very little about paleolithic life?

It looks like you deny to others the right to infer, according to their logic, the diet of our paleolithical ancestors, while you do the very same thing with the infant mortality at the very same historical time.

Another presumed fact by yours:

"Those robust skeletons hide another ugly truth. Older individuals or those who have anything wrong with them quickly fall by the wayside when living a migrant paleolithic lifestyle. There is no way a hunting gathering band can carrying along people who can't walk many miles every day."

My opinion is that no one in his right mind would let knowledge go away, and let grandpa/ma or the tribal shaman behind because he/she broke his/her leg, or lost part of his leg to a smilodon.

There are the remains of a man that was probably over 50 years old when he died, part of the forearm was missing, and it's presumed that couldn't walk for long distances. He probably lost it years before his death, indicating that he was cared for for long periods of time, probably years. If I remember well, it is one of the "shanidar" skeletons.

Agreed, it's only one, or the only one I'm aware of, but it's a hint on how a hunting/gathering society treated chronic diseased/crippled tribe members.

It's my impression that you fall into the same trap than the people you critizise.

The two paragraphs are just as an example, as I see through other parts of the article your personal opinion, put as scientific fact.

There surely are the typical PIAs you'll find in any specific group of humans, that must evangelize everyone, within the low carb community. They're surely not better than the "healthy, varied diet" evangelists.

I do low carb because I have great control and numbers, overall, with it. Perhaps diabetics aren't as adapted as non diabetics to a high carb diet, which I view as consuming more than 100gr of carbs per day.

Conguitos, you said From actual knowledge from human DNA data, it looks like that your assesment is incorrect and that around 100'000 to 60'000 years ago, probably there were less than 20'000 humans alive, because the Toba eruption event.

I'm neither anthropologist nor historian. Could you please enlighten me regarding the means of determining population from DNA, and could you also explain the significance of the Toba eruption? Thanks in advance.

I started principally by low carbing to control my errant BG, but then arose the question of what to replace the missing carbs with.

I've tinkered with my diet considerably over the last five years or so, and have gone by RESULTS.

The correct balance of macronutrients which has not only improved my BG but also my BP and lipids seems to be remarkably similar to a Primal/Paleo diet, and the exercise regime which works best *for me* is a combination of long walks and brief heavy lifting: this doesn't freak out my BG or (looking at my lipid panels) insulin resistance or generate those gnawing hungers and carb cravings I used to suffer from.

Yeah there are those "more Paleo than thou" folks, just like the lipophobes and carbophiles, but it's hard to argue with numbers that support the research of the likes of Stephan and Peter in the dietary field, or Mark Sisson and Chris (Conditioning Research) in the exercise field. Most of these people have derived their theories from study of ancient civilisations, modern hunter gatherers and more importantly what changed to cause them to adopt "modern" diseases.

Case in point, a recent (vegetarian) visitor ran round the village before breakfast and then went face down in the carbs. His medications are now increasing. I *walk* round the village, then shift some heavy things around for a while, my BG stays mostly in range and my lipids and BP have improved markedly and stayed improved, and I seldom need to snack between meals: my meds have stayed much the same for those five years.

Like "Test Test Test" the feedback is uber-important in determining what works for *you*. It just so happens that a Primal-type lifestyle seems to work for me, it seems to do what is claimed and shut down expression of the "emergency" genes which are chronically expressed by Modern Civilisation, including the wheat, fructose, Omega 6s and overuse of cardio, to name but a few.

If it doesn't work for you, no problem, go find something that does! (grins)

The theory is based on analysis on the genetic diversty of human DNA and the DNA of the parasites/microorganism we host.

From actual analysis it looks like we humans have a relatively low genetic variation among individuals all over the world. Which would indicate that we all are descendants from a small group of individuals that lived around 60000 to 100000 years ago, roughly.

The molecular clock hypothesis gives us a reference for calculations. The idea is that variations in DNA happen in relatively constant periods of time, so that we're able to calculate when a genetic divergence between two populations happened. As written before, for the moment it's only an idea, which seems to work quite accurately for the human genome when comparing data from other scientific fields, like geology.

The Toba super volcano, is believed to have violently erupted some 70000 years ago, wreaking havoc all over the world.

From geologic evidence, it seems clear that the event happened at the suggested timeframe and that it was devastating, unleashing around 500 times the destructive power of all combined explosives used in WWII, including Nagasaki and Hiroshima.

Here a link to the pertinent wikipedia article on the Toba catastrophe theory:

http://en.wikipedia.org/wiki/Toba_catastrophe_theory

if you're interested for more information, you can google for the following:

I hadn't heard of the Toba incident before. The Wikipedia article is interesting, but it seems to be mostly speculation. Not all of the geologic information supports it, and at least one settlement in India seemed to survive it. Wikipedia doesn't address this in the article, but it seems that such a worldwide catastrophe would have caused a similar proportion of deaths in other predatory species. Was that the case?

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I was diagnosed with diabetes in 1998. Since then I've kept my A1cs in the 5.0-6.0% range using the techniques you'll find explained at The main Blood Sugar 101 Web Site, where you'll also find extensive discussion of the peer-reviewed research that backs up the statements you read here.

I've also published two books on related subjects, Blood Sugar 101: What They Don't Tell You About Diabetes, which was an Amazon Diabetes bestseller for 3 years and Diet 101: The Truth About Low Carb Diets.